Rogers Marvel Architects, New York. View looking north from top of escarpment.

Toronto's most celebrated modern landmark, our City Hall, will soon change. But what will the redesign of Nathan Phillips Square tell us about who Torontonians are today? Do we have the courage to accept bold designs?

Finnish architect Virilo Revell's new City Hall gave form to Toronto's mid-century modern aspirations. His vision was so successful, it is a symbol as recognized internationally as the Sydney Opera House.

Many people in our city consider it perfect. Others argue the surrounding plaza is not as powerful as the buildings it frames.

That wariness is evident in the four design proposals for the plaza revealed on Tuesday evening. Standing in the shadow of greatness can be unnerving. It also explains why the two most unself-conscious schemes are either from out-of-town designers or from young firms that don't hold back.

Plant Architect Inc. is a team already making its mark in Canadian design. Led by principals Chris Pommer, formerly with Bruce Mau Design, and Lisa Rapoport, Plant's scheme is unashamedly urban.

Pommer says their design "makes a coherent and engaging urban room inside a green perimeter." That's good, because the perimeter is now the plaza's biggest weakness. Beyond the square's signature elevated walkway, its edge is uninviting. Plant solves this problem in two key ways.

First, their proposal echoes City Hall's lobby floor design by recreating it outside on the plaza's paving system. The water-permeable paving will run edge to edge across the site, making it clear where the street ends and the square begins -- the way an area carpet defines key parts of a room.

They then line the walkway colonnade with trees and grasses to further strengthen the new edge -- a distinct natural space for year-round visitors. Entering the square becomes an experience akin to walking out of a forest into a clearing.

Their landscape design is most engaging at the west edge of the square. Here, elements such as the Peace Garden blend together with reflecting pools, trees and sculptural elements to create a place for quiet contemplation in an otherwise frenetic city.

While these design moves are strong, what impresses most about the scheme is its urbanity: There is a Helsinki-meets-Milan level of detail to Plant's urban elements that may just have pleased Revell.

The essential theatre sits on a podium of low stairs readily accommodating the square's performance functions. Nearby, roughly where the skate rental building now sits, will be a 5,000- square-foot restaurant. Its dual height space, glass walls and open roof terrace will ensure the square is a year-round destination.

The project by Rogers Marvel Architects of New York takes a contrasting approach to designing the plaza.

Much like the Harbourfront design competition winners, they, as outsiders, see Toronto as a place as much informed by the mystique of the Canadian wilderness as it is by attempts at modern urbanism. All that nature up here has to be represented in some way.

The team's big gesture is to create an elevated berm on the western edge of the plaza. Tree covered, it rises escarpment-like to embrace the walkway. An iconic, tongue-in-cheek image shows picnickers warming themselves next to a fire pit overlooking the square.

Paradoxically, below the trees is an elegant glass-edged interior space providing shelter in winter and access to a restaurant year round.

Like Plant, Rogers Marvel also makes the outer square a part of the visitor experience, so much so that they run their paving and planting scheme across the street as a much-needed gesture in front of Lennox's Old City Hall.

It is a good idea and probably will end up in the scheme no matter who wins.

Unlike Plant, this team keeps the Peace Garden where it is, an understandable gesture given the pavilion's meaning, but ultimately it confuses Revell's minimal intentions. Plant's design gives visitors more room for solitary contemplation -- something lacking in its current placement -- while also simplifying the plaza.

Is Nathan Phillips Square an intense urban experience or is it an opportunity to embrace the wilderness? The jury makes its choice on March 8.

Update: While there wasn't the space in today's newspaper for full team credits, here are further details: